How to Read a Nutrition Label for Keto (Net Carbs and Hidden Sugars)

To read a nutrition label for keto, go straight to the carbohydrate section: find Total Carbohydrate, subtract the grams of Fiber, subtract any sugar alcohols like erythritol, and what remains is your net carbs, the number that actually affects ketosis. Then scan the ingredient list for hidden sugars, because a package can hide a lot of them behind unfamiliar names. That is the whole method, and everything below explains each step.

Want to skip the math on a whole meal? Paste it into the Is My Meal Keto? checker or look up single ingredients in the keto food database.

Net carbs in one sentence

Net carbs equal total carbohydrate minus fiber minus sugar alcohols. Fiber and most sugar alcohols pass through without meaningfully raising blood sugar, which is why keto counts net carbs rather than total carbs. If you are new to this, our keto basics guide covers the fundamentals.

Step 1: Start with total carbohydrate

In the United States, the Total Carbohydrate line already includes the fiber and sugars listed beneath it, so start there. Do not confuse Sugars with total carbs; a food can list low sugars but still be high in starch, which is carbohydrate too. Starch does not always appear on its own line, so trust the Total Carbohydrate number as your ceiling.

Step 2: Subtract the fiber

Fiber is a carbohydrate your body does not digest into glucose, so keto subtracts it. If a bar lists 20g total carbohydrate and 12g fiber, that leaves 8g before any sugar alcohols. High-fiber, low-sugar whole foods are exactly why non-starchy vegetables and berries fit keto; see our low-carb vegetables list and fruit ranked by net carbs.

Step 3: Handle sugar alcohols honestly

Sugar alcohols are listed separately when present. Erythritol is absorbed so poorly that you can subtract essentially all of it. Xylitol and maltitol are different; they are partially absorbed and can raise blood sugar, so a common rule is to subtract only half of those grams. When a label lumps them together as sugar alcohols, be conservative and assume they count more than erythritol alone would.

Step 4: Read the ingredient list for hidden sugars

The numbers can look fine while the ingredient list tells a different story. Sugar hides under dozens of names. Watch for:

• Cane sugar, brown sugar, and evaporated cane juice
• Honey, maple syrup, agave, and molasses
• Anything ending in ose, such as glucose, dextrose, fructose, and maltose
• Corn syrup, high-fructose corn syrup, and rice syrup
• Maltodextrin, which spikes blood sugar despite not being called sugar

Ingredients are listed by weight, so if a sweetener appears near the top, the product is built around it. Refined starches like wheat flour count too, even though they are not sweet.

Watch the serving size

A label's numbers apply to one serving, not the whole package. A bag might show 3g net carbs but contain three servings, making the real total 9g if you eat it all. Multiply everything by how much you actually eat, and watch for oddly small serving sizes designed to make a food look lower-carb than it is. Zero sugar and keto on the front of a package are marketing claims, not a guarantee; the table sugar may be gone while refined starches remain, so the front of the box never replaces reading the back.

Putting it together

Read every new packaged food back to front: serving size, total carbohydrate, fiber, sugar alcohols, then the ingredient list. With practice it takes seconds. When in doubt, whole foods with no label at all, such as eggs, meat, fish, and leafy greens, are the safest keto choices, and you can confirm any of them in the food database.